An electric bulb is marked 220v60w. An ammeter in the circuit shows the bulb uses a current of 0.2727A. The bulb burns for an hour. Calculate the following:
A. The electrical energy consumption
B. The cost for the bulb to burn for one hour if the cost of electricity is 17.45 cents per kWh.
2.determine the power rating of a stove if it releases 200kJ of heat energy for 4 minutes and 30 seconds
(a) 60W * 1 hr = 60 Wh
(b) .060 kWh * .1745 $/kWh = 0.01
200kJ/270s = 740W
To calculate the electrical energy consumption of the bulb, we can use the formula:
Energy consumption (in kilowatt-hours) = Power (in kilowatts) x Time (in hours)
A. First, we need to calculate the power of the bulb. Given that the bulb has a voltage of 220V and a current of 0.2727A, we can use the formula for power:
Power (in watts) = Voltage (in volts) x Current (in amperes)
Power = 220V x 0.2727A
Power = 60W (as stated on the bulb)
Now, we can calculate the energy consumption:
Energy consumption = Power / 1000 (to convert from watts to kilowatts) x Time
Time = 1 hour
Energy consumption = (60W / 1000) x 1 hour
Energy consumption = 0.06 kWh
B. To calculate the cost for the bulb to burn for one hour, we need to multiply the energy consumption by the cost of electricity per kilowatt-hour (kWh).
Cost = Energy consumption x Cost per kWh
Cost = 0.06 kWh x 17.45 cents/kWh (converted to dollars)
Cost = 1.047 dollars
Therefore, the cost for the bulb to burn for one hour is approximately 1.05 dollars.
2. To determine the power rating of a stove, we can use the formula:
Power (in watts) = Energy (in joules) / Time (in seconds)
Given that the stove releases 200 kJ (kilojoules) of heat energy and the time is 4 minutes and 30 seconds, we need to convert the time to seconds:
Time = 4 minutes x 60 seconds/minute + 30 seconds
Time = 270 seconds
Now we can calculate the power:
Power = 200,000 J (converted from kJ) / 270 seconds
Power ≈ 740.74 watts
Therefore, the power rating of the stove is approximately 740.74 watts.